The goal of this Core is to provide "real fime" physiological and molecular imaging support for various experimental applicafions in this Program. The Core will provide equipment and expertise for the qualitative and quantitafive analysis of cellular and molecular interactions at two different levels: cell-cell and cellmolecular interactions in vitro, and cell-cell interactions in vivo in the context of the vessel wall. The in vitro component of this Core will give Pis access to live cell imaging capabilifies, and computer assisted image analysis, of unlabeled cells, or cells labeled with fluorescently tagged antibodies or transduced to express GFP-tagged protein. This component is referred to as the Live cell fluorescence Microscopv facility. For in vivo studies, the established Intravital Microscopv (IVM) facility in The Center for Excellence in Vascular Biology will make available state-of the art capabilities for real-time imaging ofthe microcirculation in anesthetized animals. Thus through this Core, Program investigators will leverage resources that would be too expensive for single laboratories to purchase and maintain. Importanfiy, the Core will provide expertise and technical assistance to increase the productivity of individual projects as well as increase the capabilities of the Pis to accomplish the experimental aims of each project.